Does 1996 Mustang GT 4.6L have the timing belt or chain and does it to be changed when car has 104000 miles on it?

The 1996 Mustang GT 4.6L uses a timing chain, not a belt. Timing chains generally last much longer than belts and typically don't require replacement at 104,000 miles unless there's a specific problem.

While there's no set mileage interval for chain replacement, 104,000 miles is well within the typical lifespan of a 4.6L Mustang GT timing chain. You should focus on regular maintenance like oil changes and listen for any unusual noises from the engine (rattles or metallic sounds that might indicate chain wear). If you're experiencing performance issues or unusual engine sounds then it might warrant an inspection. However, a proactive replacement at that mileage is generally not necessary.